Abstract

Microwave combined with vacuum frying (MVF) of apple slices was studied experimentally. Apple slices were fried using MVF and Vacuum frying (VF) technologies, and three microwaves (MW) power levels (800, 900 and 1000 W) were used for frying up to 14 min. The effect of frying time and MW power on moisture content, oil uptake, textural crispness and color parameters was measured and analyzed. The MW power significantly increased the moisture evaporation rate, reduced the oil uptake, increased the hardness and produced more desirable yellow color compared to VF. With increasing the MW power, the moisture evaporation rates increased significantly and at the same time MVF reduced the oil uptake compared with VF. The crispiness and yellowish color of the apple slices increased with increasing MW power and frying time respectively. Results revealed that the MW application is one of the foremost determinants that induce the quality frying of apple slices and improve the frying rate. Therefore, MVF is a helpful and promising method to intensify the frying process.